laed4 Interface

public interface laed4

This subroutine computes the I-th updated eigenvalue of a symmetric rank-one modification to a diagonal matrix whose elements are given in the array d, and that D(i) < D(j) for i < j and that RHO > 0. This is arranged by the calling routine, and is no loss in generality. The rank-one modified system is thus diag( D ) + RHO * Z * Z_transpose. where we assume the Euclidean norm of Z is 1. The method consists of approximating the rational functions in the secular equation by simpler interpolating rational functions.


Subroutines

public pure subroutine dlaed4(n, i, d, z, delta, rho, dlam, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: i
real(kind=dp), intent(in) :: d(*)
real(kind=dp), intent(in) :: z(*)
real(kind=dp), intent(out) :: delta(*)
real(kind=dp), intent(in) :: rho
real(kind=dp), intent(out) :: dlam
integer(kind=ilp), intent(out) :: info

public pure subroutine slaed4(n, i, d, z, delta, rho, dlam, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: i
real(kind=sp), intent(in) :: d(*)
real(kind=sp), intent(in) :: z(*)
real(kind=sp), intent(out) :: delta(*)
real(kind=sp), intent(in) :: rho
real(kind=sp), intent(out) :: dlam
integer(kind=ilp), intent(out) :: info

Module Procedures

public interface stdlib_dlaed4()

Arguments

None

public interface stdlib_slaed4()

Arguments

None